1. Technical Field
The present invention generally relates to counting systems. More particularly, the present invention relates to determining the number of items in a linear queue.
2. Background Art
Tracking the number of items in a queue is done in many different circumstances. For example, the number of people in a line or queue waiting to purchase goods or to otherwise be serviced. As a more specific example, retail stores monitor cashier check-out lines and open more registers when the lines get too long. Keeping lines short helps avoid the loss of customers due to the wait and may discourage shop-lifting as a method of avoiding the long lines.
Monitoring the length of lines of people waiting becomes even more important when one considers broader uses for this information. On a long-term basis, data regarding lines can be used to identify periods of higher and lower activity, in order to more effectively schedule the number of cashiers or other service people. The information could also indicate store locations in a chain of stores (or departments within a store) with poor customer service as indicated by consistently long lines. Further, the information could be combined with cash register receipts to determine an average number of people per purchasing group. Registers could be opened when a certain number of these statistical purchasing groups are in line.
In the past, the monitoring of lines of people waiting has been done in a variety of ways, all of which suffer from various inefficiencies. Such monitoring is often done visually by an employee. However, this prevents that employee from doing other more critical jobs and becomes increasingly difficult to manage as the number of customers and/or lines increases. Another way line monitoring is done is electronically. One system employs a pressure-sensitive mat with active areas and counts the number of areas currently having sufficient weight thereon. However, each person would have to be directly on one of the areas, rather than to one side, and the mats may wear out over time. Another electronic approach is to use break-beam type sensors which monitor for breaks in the light beam when people enter and exit the queue; the difference between the entrance and exit count being the number of people currently in the line. However, this requires physical delimitation of a line, two people close together when entering or exiting could be counted as one and children may fidget near the beam causing it to trigger repeatedly.
Thus, a need exists for an efficient, flexible system to monitor the number of people (or more generally, objects) in a line or queue.